Fear of my aquariums failing and causing expensive water damage. I miss my reptile days when I didn't have those worries. I had one aquatic turtle but never thought about the possibility at the time(ignorance is bliss)
ughh like many others... A tank leak That would be the biggest fear
Also an uncontrollable disease outbreak killing my fish. Although the money would suck to lose don't get me wrong but I really like my fish! their tanks are all stocked and cycled and overfiltered